NEW YORK (CNN/Money) - Blue-chip stocks edged lower Wednesday as investors played it cautious ahead of reports on manufacturing and construction spending, keeping the market from building on Tuesday's late rally.

The Dow Jones industrial average (up 51.40 to 10,173.92, Charts) and the Standard & Poor's 500 (down 1.25 to 1,102.99, Charts) index both edged lower in the early going.

The Nasdaq composite (COMP: down $4.69 to $1,833.41, Research, Estimates) was little changed.

Trading was likely to be dominated by light volume again Wednesday, as it has for the first two days of the week, due to the ongoing Republican National Convention in New York City. August is typically a big vacation month. On top of that, many New York-based Wall Street professionals are on vacation this week or are working from home.

Due shortly after the open, the Institute for Supply Management's manufacturing index is expected to have fallen to 60.0 in August from 62.0 in July.

Due around the same time, construction spending in July likely rose 0.4 percent, according to Briefing.com estimates. Spending fell 0.3 percent in June.

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Oil prices turned higher, after eight down session. Light crude prices pushed back up over $42 a barrel in electronic trading. Brent crude oil futures rose 55 cents to $40.16 a barrel in London.

Treasury prices rose, pushing the yield on the 10-year note down to 4.10 percent from 4.11 percent late Tuesday. Bond prices and yields move in the opposite direction.

In currency trading, the dollar rose against the yen and the euro.

In global trade, Asian markets closed higher Wednesday, and European markets were mostly up at midday.